[3.2.3] broken umlauts in htmx req/resp

[resmo]

Summary

I am experiencing an issue I only see with htmx responses that is why I open the issue here, but it might be a spring boot 3.2.3 issue.

After switching form spring boot 3.2.2 to 3.2.3 I see broken "umlauts". Switching back to 3.2.2 shows correct "umlauts".

Response header looks fine, content "looks" identical but the weird thing is that the content length is different, off by 1 B (3.2.3 has -1 B). Unsure if this is the issue.

Spring Boot

3.2.3

Details

3.2.3

HTTP/1.1 200 
Content-Type: text/html;charset=UTF-8
Content-Language: de
Content-Length: 214
Date: Fri, 23 Feb 2024 16:08:47 GMT
Keep-Alive: timeout=60
Connection: keep-alive

3.2.2

HTTP/1.1 200 
Content-Type: text/html;charset=UTF-8
Content-Language: de
Content-Length: 215
Date: Fri, 23 Feb 2024 16:14:01 GMT
Keep-Alive: timeout=60
Connection: keep-alive

I use the Thymeleaf with spring-boot-htmx (and issue also filed there wimdeblauwe/htmx-spring-boot#99).

[philwebb]

This is unlikely to be an issue in Spring Boot itself, but it could be caused by a dependency upgrade that we manage. I would suspect Spring Framework or Tomcat would be the most likely candidates.

@resmo Do you have a small reproducer project that you can provide? This might help us identify what's changed.

[resmo]

I created a reproducer and can say, that I am only able to reproduce it in 3.2.3 using the helper library io.github.wimdeblauwe -> htmx-spring-boot

reproducer repo https://github.com/resmo/spring-boot-3.2.3-demo-htmx-umlauts

[scottfrederick]

See wimdeblauwe/htmx-spring-boot#99

[scottfrederick]

@resmo I've tried your reproducer, and I see the umlauts when clicking on both links regardless of the Spring Boot version. I've tested it in Chrome and Firefox, running the app with ./mvnw spring-boot:run or java -jar target/repro-0.0.1-SNAPSHOT.jar. Are there additional instructions for running the app that you can provide?

Also, can you try setting the property <spring-framework.version>6.1.3</spring-framework.version> in the <properties> section of your pom.xml when building against Spring Boot 3.2.3? Framework was upgraded from 6.1.3 to 6.1.4 between Boot 3.2.2 and 3.2.3, so forcing the downgrade with Boot 3.2.3 would help narrow down the root of the problem.

[resmo]

@scottfrederick

I've tried your reproducer, and I see the umlauts when clicking on both links regardless of the Spring Boot version. I've tested it in Chrome and Firefox, running the app with ./mvnw spring-boot:run or java -jar target/repro-0.0.1-SNAPSHOT.jar. Are there additional instructions for running the app that you can provide?

very interesting: you did everything the way I did, but as it seems the issue is related to the language setting in the browser: if I change the default language to "english", all umlauts look good. If I change it to "german" or "german (switzerland)", I see the issue.

tested in chromium, firefox on linux and firefox on mac

adding <spring-framework.version>6.1.3</spring-framework.version> to properties in pom does "fix" the issue

I browsed through the list of issues and noticed spring-projects/spring-framework#32317 which looks suspicious. I try to test the snapshot of 6.1.5 once it is available.

[scottfrederick]

Thanks for the follow-up @resmo. I will close this issue, as it doesn't appear that Spring Boot is the cause.

[sbrannen]

I browsed through the list of issues and noticed spring-projects/spring-framework#32317 which looks suspicious. I try to test the snapshot of 6.1.5 once it is available.

@resmo, please note that 6.1.5-SNAPSHOT builds for Spring Framework are already available.

See spring-projects/spring-framework#32317 (comment) for details.

Feedback is welcome!

[resmo]

@scottfrederick Thanks for your time.
@sbrannen I tested with spring-core-6.1.5-20240225.154205-16.jar but unfortunately it doesn't resolve the issue.

[wilkinsona]

Re-opening to continue the investigation. The problem reminds me a little of #32472 and #32472 (comment) in particular. However, unless Tomcat changed its mappings in a maintenance release, I wouldn't expect to see the described change in behavior.

[resmo]

@wilkinsona let me know if I can help, to me it looks related to accept-language header somehow

[sbrannen]

Andy, I think it might be due to the fact that the content type is now cached.

See the analysis from a user in the linked Framework issue which I’ll investigate this afternoon.

[wilkinsona]

Thanks, Sam. To avoid duplicating effort, I'll close this one again for now. Let us know how this afternoon's investigation goes. We can re-open this one again if needed.

[sbrannen]

We've pushed a fix for Spring Framework 6.1.x.

See spring-projects/spring-framework#32317 (comment) for details.

[resmo]

@sbrannen spring-core-6.1.5-20240226.173247-18.jar fixes the issue, umlauts are shown correctly (content-length size is as it was in 6.1.3)

Thanks!